Karl gerstmann



(no Model.)

K. GERSTMANN. APPARATUS FOR OPENING DOORS.

No; 564,880. Patented July 28, 1896.

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UNITED STATES PATENT OFFICE.

KARL GERSTMANN, OF FREIBURG, GERMANY.

APPARATUS FOR OPENING-DOORS.

SPECIFICATION forming part of Letters Patent No. 564,880, dated July 28, 1896. Application filed March 27, 1895. Serial Ho. 543,394. (No modeli) Patented in England March 30, 1895, No. 3,671.

To all whom it may concern:

Be it known that I, KARL GERSTMANN, master locksmith, of 16 Egonstrasse, Freiburg, in the Empire of Germany, have invented new and useful Improved Apparatus for Opening Doors and the Like, (patented to me in Great Britain March 30, 1895, No. 3,671,) of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to an apparatus for opening, unlocking, or unlatching doors and the like in which the power requisite for opening the latch is obtained by the compression of a spring on the complete opening of the door by any person passing through. This controlling-spring is capable of being disengaged from any-desired point by the operation of an electromagnet whereby the lock of the door is opened.

My improved apparatus is illustrated in the accompanying drawings, in which- Figure 1 is an enlarged side view, part-1y in section, of the apparatus. Fig. 2 is a transverse section of Fig. 1 in the plane indicated by the dotted line thereon. Fig. 3 is a view of a door equipped with the apparatus.

The apparatus consists of a casing 0, adapted to rotate in fixed bearings 12, attached to a plate a, and having an angular recess 1 and an arm d, the free end of which carries a roller e, adapted to'work in a guide 8, provided on the door. A casting fis arranged below casing c, and has a tooth-like projection g, adapted to fit in the recess 1" in the casing 0. Casting f is attached to a slide h, playing in a slot in the plate a. A rod '5 is fixed to the casting f and extends into and through casing 0, and is guided in the closing screw-plug k of the casing c. This rod carries a disk Z, against which a spiral spring m, contained in the case 0, bears. Whenthe two casings are in engagement with each other and the door is opened, the casing c is moved round through the action of the arm 01 and presses with the inclined face of its recess 0" against the inclined face of the tooth-like projection g on' casting f, which causes the latter to move downward, by which movement the free end of the lever n becomes caught by the pivoted hookcatch 0, which is so arranged that when locked it will prevent upward movement of the casting f, which is now under the influence of the spring m. On closing the door, the casing f remains in the position illustrated in the drawings. Catch 0 has a long arm underlying electromagnets p, which are suitably connected by means (not shown) to a circuit-closer located at any point from which it may be desired to open the door. Now, if admittance is desired, the circuit through electromagnet p is closed and the magnet being energized oscillates catch '0, which releases hook or, whereupon the spring draws the casing f with its tooth-like projection G into the recess '1' in the casing c, which movement is transmitted by means of the bell-crank lever g and any suitable connection to the latch of the door, so as to open the latter, while by the further opening of the door the movement of the arm cl serves to again reset the apparatus.

I wish it to be particularly understood that I do not limit myself to the precise details of construction hereinbefore described and illustrated by the accompanying drawings, but that I hold myself at liberty to make such changes and alterations as fairly fall within the spirit and scope of my invention.

I claim- 1. The combination of a spring which is by the opening of the door puts the spring.

under tension, connections between the m0vable casting and the latch, and meansfor releasing said casting, substantially as described.

3. The combination of the door, the sliding casting f, the spring m and rod 1', the rotary casing 0, connected to the door by arm cl, the latch h, hook o, lever a, magnet 12, and

connections between the casting and the electromagnets 1), all substantially as and for 10 door-latch, all substantially as described. the purpose described.

4. The herein-described operating device In witness whereofI have hereunto set my for door-latches, consisting of the casing 0 hand in presence of two witnesses. having notch 'r and arm 01 engaging the door;

the sliding casting f having tooth g, the rod KARL GERSTMANN. 'i and spring mfor operating the casting; and Witnesses: V the connections between said casting and JOSEF ZENETNER,

door-latch; with the lever 41-, hook 0, and SEBASTIAN UTZ. 

